1. Field of the Invention
The present invention relates to an electric power supplier, a method for controlling supplying of electric power, and an information processing device.
2. Description of the Related Art
An electric power supplier for use in an information processing device, such as a personal computer and the like, includes an AC-DC converter, DC-DC converter, etc.
The electric power supplier converts an alternating voltage into a direct-current voltage, using the AC-DC converter, and converts an output voltage value of the AC-DC converter into a plurality of direct-current voltage values, using the DC-DC converter. Output voltages of the DC-DC converter are sent to each section included in the information processing device, such as a CPU (Central Processing Unit), memory, hard disk drive, etc.
Conventionally, the electric power supplier supervises whether the AC-DC converter is overloaded, and includes a current detection circuit and a detection resistor so as to avoid such an overloaded state of the AC-DC converter. The detection resistor is formed on a power supplying line for supplying electric power from the AC-DC converter to the DC-DC converter. The current detection circuit detects a current flowing through the resistor for detection, controls the DC-DC converter and reduces the output voltage of the DC-DC converter in the case where the detected current value exceeds a rated current value of the AC-DC converter (i.e. in the case where an overcurrent flows through the detection resistor).
However, in the conventional electric power suppliers, in the case where the AC-DC converter is prevented from being in an overloaded state, a reduction occurs in the voltage to be supplied to each section included in the information processing device, such as the CPU, etc. Hence, the electric power lacks in those devices, such as the CPU, memory, and the like which require sufficient electric power to operate.
The present invention has been made in consideration of the above. It is accordingly an object of the present invention to provide an electric power supplier which can continuously supply a predetermined load of the supplier with electricity required by the load, a method for controlling supplying of electricity and an information processing device.
In order to achieve the above object, according to the first aspect of the present invention, there is provided an electric power supplier comprising:
an alternating/direct-current conversion circuit which converts an alternating voltage into a direct voltage, and outputs a converted voltage;
a first path, one end of which is connected to the alternating/direct-current conversion circuit, and other end of which is connected to a first load, the first path supplying output voltage of the alternating/direct-current conversion circuit to the first load;
a second path, one end of which is connected to the first path, and other end of which is connected to a second load, the second path supplying output voltage of the alternating/direct-current conversion circuit to the second load;
a switch circuit which is formed in the second path; and
a current detection circuit which detects a value of a current flowing a portion of the first path between the alternating/direct current conversion circuit and a node between the first path and the second path, and controls the switch circuit to electrically connect or disconnect the node to or from the second load, based on a detected current value.
The current detection circuit may control the switch circuit to electrically connect or disconnect the node to or from the second load, based on a difference between the detected current value and a predetermined current value, so that the detected current value becomes lower than the predetermined current value.
The current detection circuit may control the switch circuit to electrically connect or disconnect the node to or from the second load, in accordance with at least one of the difference between the detected value and the predetermined current value, an integrated result of the difference, and a differentiated result of the difference.
The current detection circuit may control the switch circuit to electrically disconnect the node from the second load, in a case where the detected value of the current is equal to or larger than a reference value which is an output current value of the alternating/direct-current conversion circuit being overloaded, and to electrically connect the node to the second load, in a case where the detected value of the current is lower than the reference value.
The current detection circuit may include a passive element which is formed in a portion of the first path located between the alternating/direct-current conversion circuit and the node, and detect a value of a current flowing through the passive element, and compare a detected value of the current with the reference value.
The current detection circuit may include a current control circuit which:
generates a control signal for controlling an operation of the switch circuit, based on a voltage generated across the passive element; and
supplies the switch circuit with a generated control signal; and
wherein the switch circuit may electrically connect or disconnect the node to or from the second load, in accordance with the control signal.
The passive element may comprise a fuse.
The passive element may comprise a coil included in a noise filter.
A signal may represent whether the second load is possible to electrically be disconnected from the node; and
the current control circuit may generate the control signal for controlling an operation of the switch circuit, in a case where a current flowing through the passive element is equal to or larger than the reference value and the signal sent from the second load represents that the second load is possible to electrically be disconnected from the node.
The first load may comprise a voltage-value conversion circuit which converts a voltage having a value of the alternating/direct-current conversion circuit into voltages having a plurality of values, and outputs the plurality of voltage.
The voltage-value conversion circuit may be connected to an information processing unit including a microprocessor and a memory.
The second load may comprise a battery circuit including a secondary battery; and
the battery circuit may detect whether the secondary battery is fully charged with electricity, and send a detection signal which represents detection results to the current control circuit; and
the current control circuit may generate the control signal for electrically disconnecting the node from the second load, in a case where the current flowing through the passive element is equal to or larger than the reference value and the detection signal represents that the secondary battery is fully charged.
In order to achieve the above object, according to the second aspect of the present invention, there is provided a method for controlling supplying of electric power, comprising:
sending electric power to a first load from a power circuit via a first path;
sending electric power to a second load from the power circuit via a second path connected to the first path;
detecting a value of the electric power sent from the power circuit to the first and second loads; and
electrically connecting and disconnecting a node between the first and second paths to or from the second load, based on a detected value of the electric power.
The electrically connecting and disconnecting may include:
electrically connecting and disconnecting the node to or from the second load, so that the detected value of the power becomes equal to or lower than the predetermined value, based on a difference between the detected value and a predetermined value of the power.
The electrically connecting and disconnecting may include:
electrically connecting or disconnecting the node to or from the second load, in accordance with at least one of the difference between the detected value of the power and the predetermined value of the power, an integrated result of the difference, and a differentiated result of the difference.
The electrically connecting and disconnecting may include:
electrically disconnecting the node from the second load, in a case where the detected value of the electric power is equal to or higher than a reference value which is output power of the power circuit being overloaded; and
electrically connecting the node to the second load, in a case where the detected value of the electric power is lower than the reference value.
The detecting may include:
detecting a value of output power of the power circuit, based on a value of a current flowing through a passive element which is formed in a portion of the first path between the power circuit and the node; and
comparing a detected value with the reference value.
The detecting may include:
generating a control signal for controlling an operation of a switch circuit which is formed in the second path;
sending the control signal to the switch circuit; and wherein
the electrically connecting and disconnecting may include connecting and disconnecting the node to or from the second load by controlling the switch circuit, in accordance with the control signal.
The passive element may comprise a fuse, or a coil included in a noise filter.
The sending the control signal includes:
accepting a permitting signal, for permitting the second load to electrically be disconnected from the node; and
generating the control signal for controlling an operation of the switching circuit, in a case where the detected value of the power is equal to or higher than the reference value and the permitting signal sent from the second load represents that the second load is possible to electrically be disconnected from the node.
In order to achieve the above object, according to the third aspect of the present invention, there is provided an information processing device comprising:
the electric power supplier according to claim 1; and
an information processing unit which is connected to the electric power supplier and driven by a voltage, applied thereto and sent from the electric power supplier; and
wherein the information processing unit includes
a memory which stores information,
an operational input section which inputs an instruction,
an input/output control section which performs inputting and outputting processing,
a display section which displays information, and
a processor which supervises a state of the operational input section through the input/output control section, reads out information from the memory and/or an external memory, executes processing based on read information, and controls the display section to display information corresponding to executed processing.